| 
 | 
 | 
A program initiated by F. Klein in an 1872 lecture to describe geometric structures in terms of their group Automorphisms.
References
Klein, F.  ``Vergleichende Betrachtungen über neuere geometrische Forschungen.''  1872.
 
Yaglom, I. M.  Felix Klein and Sophus Lie: Evolution of the Idea of Symmetry in the Nineteenth Century.
  Boston, MA: Birkhäuser, 1988.